This paper presents the investigation are the static and dynamic longitudinal stability of a small flying boat in cruise
flight for different cruise heights and speeds. After that, we use two methods to control the height of a flying boat: fuzzy
logic controller and its compound with Proportional-Integral-Derivative (PID). The main advantage of using fuzzy
controlling methods is that the control system has more flexibility compared with conventional model based controllers.
For accomplish designing of height hold control system of a flying boat, we use a precise model of wing-in-groundeffect
vehicles in state-space form and aerodynamics derivatives of a flying boat. The controller is tested on a
simulation level in Matlab. Simulation results were promising and showed improvement in performance and accuracy
in comparison to conventional methods.